<html><head></head><body><div class="yahoo-style-wrap" style="font-family:Helvetica Neue, Helvetica, Arial, sans-serif;font-size:13px;"><div dir="ltr" data-setdir="false">Hello,</div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">I am a beginner in pdal, python or any code based programs. I have worked with LiDAR point cloud but under terrascan/microstation in the past. Recently I have discovered this tool (PDAL) and I would like to learn to use it and to be able to create a complete classification pipeline. I have a problem though. I cannot understand how or where HeightAboveGround dimension is created. No matter what I did I could not see this dimension in a *.las file. Is it a virtual attribute(dimension)?, *.las file is not appropriate file type?...I have no idea. Hope that the question is not completely stupid. <span>Any enlightenment will be well received. Thank you.</span></div><div dir="ltr" data-setdir="false"><span><br></span></div><div dir="ltr" data-setdir="false"><span>Regards,</span></div><div dir="ltr" data-setdir="false"><span>S<br></span> </div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false">This is written on pdal website<br></div><div dir="ltr" data-setdir="false"><div><h1>filters.<span class="ydpa746ac45highlighted">hag</span>_delaunay<a class="ydpa746ac45headerlink" href="https://pdal.io/en/2.7-maintenance/stages/filters.hag_delaunay.html#filters-hag-delaunay" title="Link to this heading" rel="nofollow" target="_blank"></a></h1>
<p>The <strong>Height Above Ground Delaunay filter</strong> takes as input a point cloud with
<code class="ydpa746ac45docutils ydpa746ac45literal ydpa746ac45notranslate"><span class="ydpa746ac45pre">Classification</span></code> set to 2 for ground points. It creates a new dimension,
<code class="ydpa746ac45docutils ydpa746ac45literal ydpa746ac45notranslate"><span class="ydpa746ac45pre">HeightAboveGround</span></code>, that contains the normalized height values.</p></div><br></div><div dir="ltr" data-setdir="false"><br></div><div dir="ltr" data-setdir="false"><br></div></div></body></html>